The present invention generally relates to the disinfecting and testing the electrical safety of a transesophageal echo probe.
Transesophageal echo (TEE) cardiography is an established technique in the area of cardia imaging and involves the insertion of an ultrasound TEE probe into a subject""s esophagus to scan the heart from inside the esophagus. An ultrasound TEE probe may be formed by modifying an endoscope, whereby an ultrasound transducer array is affixed to the distal end of the endoscope. Typically, the TEE probe is used with an ultrasound imaging system having electronics for remote excitation of the array to obtain cross-sectional images of the heart along a variety of scan planes as is well known.
Several TEE probes are described in the art, e.g., in xe2x80x9cTransesophageal Cross-Section Echo cardiography With a Phased Array Transducer Systemxe2x80x9d by Schluter et al., wherein an ultrasound TEE probe having a rotatable array is suggested for obtaining an improved assessment of left ventricular morphology, U.S. Pat. No. 4,543,960 to Harui et al. describing an ultrasound TEE probe having a rotatable array, U.S. Pat. No. 5,176,142 to Mason, or U.S. Pat. No. 5,176,142 to Fearnside et al.
Before an application, the TEE probe needs to be disinfected. The disinfection process is quite time consuming (generally 20 min up to 60 min) dependent on the respective disinfection fluid. In case that the TEE probe is kept in the disinfection fluid longer than needed, the life time of the TEE probe will strongly decrease.
Various cleaning apparatus for endoscopes are disclosed e.g. in EP-A-0038168, ER-A-2705896 and DE-A-3334999 U.S. Pat. No. 5,558,841 discloses a washing/sterilizing apparatus for an endoscope comprising a receptable adapted to receive the endoscope, means for supplying the receptable with a disinfection fluid, means for supplying the receptable with a rising fluid, and removing means for removing any fluid from the receptable.
Further more for the sake of patients"" safety, it is important to perform an insulation test before using the TEE probe, such as IEC 601 or a test based thereon. The insulation test generally measures a leakage current between a reference potential and a shielding of the TEE probe. The shielding of the TEE probe normally mechanically surrounds and electrically shields the TEE probe and is coated with an insulating layer.
There is a lot of care, maintenance, and at least from time to time a safety check, necessary to keep the TEE probe working precisely and ensure a long lifetime. If the TEE probe is handled with the required care, an extended lifetime of up to 12 months can be achieved. It is desired to reduce high follow-up costs due to an early TEE probe exchange.
A disinfection and electrical test equipment for TEE probes is suggested in a technical information brochure of Svenska servicedepan, Malmo, Sweden. The disclosed TEE probe tester consists of a laminate board with two acrylic tubes, one for disinfection and one for rinsing, which must be mounted about 30 cm above the floor. The TEE probe tester is used to disinfect the TEE probe and at the same time to test the electrical safety, indicating whether the TEE probe needs to be tested for leakage by qualified technical personnel. For testing the electrical safety, the measuring part of the TEE probe tester uses the disinfection fluid available during the disinfection of the TEE probe as electrical contact medium. After disinfecting the TEE probe has to be removed from the TEE probe tester, inserted into a rinse tube, and rinsed off therein from the disinfection fluid. However, the disclosed TEE probe tester is not safe enough for clinical applications and does not provide a reliable disinfection and electrical testing.
NL-A-8800755 discloses an apparatus for sterilizing and testing the electrical safety of an ultrasonic probe for diagnostic purposes. The probe is inserted in a holder with a sterilizing fluid. Simultaneously to the sterilizing of the probe, an electrical leakage test of the probe is executed.
It is an object of the invention to provide an improved disinfection and electrical test equipment for TEE probes.
According to the invention, an apparatus for disinfecting and testing the electrical safety of a TEE probe comprises a receptacle adapted to receive the TEE probe, first supplying means for supplying the receptacle with a disinfection fluid, second supplying means for supplying the receptacle with a rinsing fluid, removing means for removing any fluid from the receptacle, and an insulation tester having a first contact within the receptacle and a second contact connectable with the TEE probe.
The disinfecting and testing of the electrical safety of the TEE probe is executed by supplying the receptacle with a disinfection fluid, disinfecting the TEE probe, and removing the disinfection fluid from the receptacle. The receptacle is then supplied with a rinsing fluid and the TEE probe is substantially rinsed from remaining disinfection fluid. When the TEE probe has been rinsed to a certain extent and before removing the rinsing fluid from the receptacle, an electrical safety test is executed with the TEE probe by using the rinsing fluid.
The TEE probe tester allows a reproducible and safe disinfection of the TEE probe and also ensures that the electrical requirements of the TEE probe are kept. The invention ensures a qualitative constant process in disinfection and thus the patients"" safety for every application of the TEE probe. The TEE probe tester according to the invention also reduces the time required for the personnel to execute the disinfection process, and further extends the lifetime of the TEE probe due to the controlled execution of the disinfection process.
The TEE probe tester may be provided as a fully automatic device, so that all process steps are carried out automatically and do not require any manual aid.
In a preferred embodiment, a plurality of rinsing cycles is applied for cleaning the TEE probe, whereby either the same or different rinsing fluids may be used during each rinsing cycle and the rinsing might be exchanged between each rinsing cycle. In that case, the electrical safety test is preferably executed during a last rinsing cycle. This makes sure that the disinfecting fluid is removed and washed out to a maximum extent, so that the electrical safety test is carried out substantially in the pure rinsing-fluid. This allows a higher reproducibility and reliability of the results from the electrical safety test.
In another preferred embodiment, the conductance of the fluid in the receptacle is measured before executing the electrical safety test. This allows, e.g., to adapt measuring parameters of the electrical safety test to the determined conductance. This leads to an increased reliability of the measuring results since the conductance of the rinsing fluid might differ dependent on the quantity of remaining disinfectant, or on the different quality of the rinsing fluid, e.g., in case that tap water is used as rinsing fluid. Also, a further rinsing cycle might be initiated in case that the determined conductance lies beyond a predefined value, so that it can be expected that there is too much remaining disinfectant in the receptacle.
In another preferred embodiment, a self-test is executed, whereby the self-test is preferably carried out before each disinfection and insulation check, or dependent on the numbers of executed disinfections and insulation checks, or on a fixed time base.
In another preferred embodiment, a concentration of the disinfection fluid is determined and a disinfection time is set or can be set in accordance with the determined concentration. This supports a fully automated and reliable process.